If the meter changes
Confirm no fixture, appliance, irrigation system, or automatic refill used water. A repeatable change supports further investigation.
Homeowner meter guide
How to check your water meter for a possible leak
A controlled no-use check can show whether metered water moved while expected use was off. It cannot identify the fixture or pipe by itself.
Four careful steps
Run a controlled meter check
- Find and read the meter safely
Record the numbers and units or take a clear photo. Follow the City of San Diego’s meter guidance; avoid operating utility-owned valves.
- Stop expected water use
Do not run taps, toilets, appliances, irrigation, or automatic refill systems during the check.
- Wait and read again
EPA WaterSense suggests comparing readings after a two-hour no-use period.
- Interpret the change cautiously
Movement suggests water was used during the interval. Recheck expected uses before assuming a hidden line leak.
Interactive homeowner tool
Water meter reading calculator
Use the readings from your no-use check to see how much the meter changed. Keep both readings in the same unit; the result shows recorded use, not where it happened.
01Record the startNote every visible digit and the unit.
02Pause normal useKeep taps, appliances, and irrigation off.
03Record the endRead the same display after the quiet interval.
Enter your numbers
Compare the two readings
City of San Diego meters measure cubic feet. The City says one cubic foot is about 7.5 gallons. See the City meter guide. Last reviewed: .
Interpretation
What meter behavior can—and cannot—tell you
A meter result is one piece of evidence, not a diagnosis.
If it stays still
Small or intermittent problems may not register during one check. Compare the result with symptoms and repeat at an appropriate time.
What it does not locate
The reading cannot separate slab, wall, fixture, irrigation, or buried-line use. A targeted test or professional isolation may be needed.
Next step
Choose the next check based on the pattern
No clear locationCompare symptom clusters and alternatives.Yard or service-line clueLearn how the meter-to-house route is investigated.Warm floor or slab clueReview the under-slab diagnostic path.Wall or ceiling clueReview concealed-moisture source testing.Need professional isolationSee what each method can establish.Discuss your readingsShare the exact start, end, time, and units.
What prompted the meter check?
- A bill increase? Use the high water bill checklist to separate ordinary use from unexplained flow. If pressure also dropped, compare low pressure with a high bill.
- Outdoor moisture? The wet-yard guide compares irrigation with a buried line. If water is collecting in the meter box, the City-side versus property-side guide explains why the utility should assess an uncertain meter-area leak.
- A measured flow rate? See how hidden water loss adds up before treating a calculation as a diagnosis.
Straight answers
Water meter test questions
How long should I wait between readings?
EPA WaterSense describes a two-hour no-use period as a homeowner check. Make sure fixtures, irrigation, and appliances do not use water during the interval.
Does movement tell me where the leak is?
No. It shows recorded use during the check. Toilets, irrigation, appliances, and hidden piping can all be involved; isolation is a separate step.
What if the reading does not change?
A stable reading during one interval does not rule out a small or intermittent leak. Repeat when the symptom is occurring and consider other evidence.
Meter changed with normal use off?
Record the readings, interval, units, and any automatic water use, then call to discuss a focused next step.